This proposal involves a multi-disciplinary multi-professional research approach to childhood malignancies. This proposal is supported by a clinical research and laboratory research team in a university affiliated pediatric medical center which has been involved in the Pediatric Oncology Group and its predecessor, the Southwest Oncology Group since 1965. Special emphasis is given to the combination of chemotherapy with other modalities of therapy including radiation therapy and surgery. The pediatric oncology team includes three pediatric hematologists-oncologists, 2 hematopathologists, a pediatric pathologist, a complete pediatric subspecialty surgical team (including a general pediatric surgeon, pediatric neurosurgeon, pediatric urologist, a pediatric oncologic orthopedic surgeon and a pediatric gynecologist), 3 pediatric neurologists, a pediatric radiation therapist, 2 pediatric social workers, a pediatric oncology nurse and 2 data managers. All patients under 20 years of age with a malignancy who are admitted to the Cleveland Clinic are offered the opportunity to take part in POG protocols if one is open for their particular disease. Members of the team are not only actively involved in both protocol development and design and the development of further studies in the Pediatric Oncology Group. The team has recently become involved in Phase I trials of new drugs as well as Phase II and Phase III studies.